1. Field of the Invention
This invention relates to the storage and reproduction of high frequency signals and more specifically to systems and methods for the storage and accurate reproduction of pulses of microwave energy.
2. Description of the Prior Art.
In the past, storage of signals at radio frequencies, and specifically storage of pulses of microwave energy, has been shortterm storage, at best, and has been accomplished by means of various delay lines, distributed electrical parameter delay lines and recirculating delay lines. Further, this invention allows storage, not only of the average frequency of the microwave pulse, but also storage of the instantaneous frequency. Thus, microwave pulses having phase, frequency or amplitude modulation may be stored and then recovered at a later time. Storage for long, indefinite periods was not possible prior to this invention, insofar as is known. In various situations where signal analysis is desired, for example in laboratory experimentation and in electronic countermeasures systems, it is desirable to be able to store signals for long periods of time and to then be able to reproduce the original signals with accuracy and fidelity as to amplitude, frequency and phase. Magnetic recording systems are limited in their frequency capabilities to 5 to 7 MHz. Today, radiated signals in the GHz frequency range and having complex modulations are of interest but equipment for long-term storage and reproduction of such microwave signals has not been available.